Uv-Dropout Galaxies In The Goods-South Field From Wfc3 Early Release Science Observations,
2010
University of Massachusetts - Amherst
Uv-Dropout Galaxies In The Goods-South Field From Wfc3 Early Release Science Observations, N Hathi, R Ryan, S Cohen, H Yan, R Windhorst, P Mccarthy, R O'Connell, A Koekemoer, M Rutkowsk, B Balick, H Bond, D Calzetti
Astronomy Department Faculty Publication Series
We combine new high sensitivity ultraviolet (UV) imaging from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) with existing deep HST/Advanced Camera for Surveys optical images from the Great Observatories Origins Deep Survey (GOODS) program to identify UV-dropouts, which are Lyman break galaxy (LBG) candidates at z sime 1-3. These new HST/WFC3 observations were taken over 50 arcmin2 in the GOODS-South field as a part of the Early Release Science program. The uniqueness of these new UV data is that they are observed in three UV/optical (WFC3 UVIS) channel filters (F225W, F275W, and F336W), which allows …
Nearby Galaxies With Spitzer,
2010
University of Massachusetts - Amherst
Nearby Galaxies With Spitzer, D Calzetti
Astronomy Department Faculty Publication Series
We review the main advances brought by the Spitzer Space Telescope in the field of nearby galaxies studies, concentrating on a few subject areas, including: (1) the physics of the Polycyclic Aromatic Hydrocarbons that generate the mid–infrared features between 3.5 ìm and 20 ìm; (2) the use of the mid– and far–infrared emission from galaxies as star formation rate indicators; and (3) the improvement of mid–infrared diagnostics to discriminate between thermal (star–formation)and non–thermal (AGN) emission in galaxies and galaxy centers.
Galactic Outflows And The Kinematics Of Damped Lyman Alpha Absorbers,
2010
University of Massachusetts - Amherst
Galactic Outflows And The Kinematics Of Damped Lyman Alpha Absorbers, S Hong, N Katz, R Dave, M Fardal, D Keres, B Oppenheimer
Astronomy Department Faculty Publication Series
The kinematics of damped Lyman alpha absorbers (DLAs) are difficult to reproduce in hierarchical galaxy formation models, particularly the preponderance of wide systems. We investigate DLA kinematics at z=3 using high-resolution cosmological hydrodynamical simulations that include a heuristic model for galactic outflows. Without outflows, our simulations fail to yield enough wide DLAs, as in previous studies. With outflows, predicted DLA kinematics are in much better agreement with observations. Comparing two outflow models, we find that a model based on momentum-driven wind scalings provides the best match to the observed DLA kinematic statistics of Prochaska & Wolfe. In this model, DLAs …
Detection Of An Ultra-Bright Submillimeter Galaxy In The Subaru/Xmm-Newton Deep Field Using Aztec/Aste,
2010
University of Massachusetts - Amherst
Detection Of An Ultra-Bright Submillimeter Galaxy In The Subaru/Xmm-Newton Deep Field Using Aztec/Aste, S Ikarashi, K Kohno, Je Aguirre, I Aretxaga, V Arumugam, Je Austermann, Jj Bock, Cm Bradford, M Cirasuolo, L Earle, H Ezawa, H Furusawa, J Furusawa, J Glenn, B Hatsukade, Dh Hughes, D Iono, Rj Ivison, S Johnson, J Kamenetzky, R Kawabe, R Lupu, P Maloney, H Matsuhara, Pd Mauskopf, K Motohara, Ej Murphy, K Nakajima, K Nakanishi, Bj Naylor, Ht Nguyen, Ta Perera, Ks Scott, K Shimasaku, T Takagi, T Takata, Y Tamura, K Tanaka, T Tsukagoshi, Dj Wilner, Gw Wilson, Min Yun, J Zmuidzinas
Astronomy Department Faculty Publication Series
Abstract: We report the detection of an extremely bright ($\sim$34 mJy at 1100 $\mu$m and $\sim$73 mJy at 880 $\mu$m) submillimeter galaxy (SMG), AzTEC-ASTE-SXDF1100.001 (hereafter referred to as SXDF1100.001), discovered in 1100 $\mu$m observations of the Subaru/XMM-Newton Deep Field using AzTEC on ASTE. Subsequent CARMA 1300 $\mu$m and SMA 880 $\mu$m observations successfully pinpoint the location of SXDF1100.001 and suggest that it has two components, extended (FWHM of $\sim$4^{\prime\prime}) and compact (unresolved) ones. Z-Spec on CSO has also been used to obtain a wide band spectrum from 190 to 308 GHz, although no significant emission/absorption lines are found. The derived …
An Aztec 1.1-Mm Survey For Ulirgs In The Field Of The Galaxy Cluster Ms 0451.6-0305,
2010
University of Massachusetts - Amherst
An Aztec 1.1-Mm Survey For Ulirgs In The Field Of The Galaxy Cluster Ms 0451.6-0305, Jl Wardlow, I Smail, Gw Wilson, Min Yun, Kek Coppin, R Cybulski, Je Geach, Rj Ivison, I Aretxaga, Je Austermann, Ac Edge, Gg Fazio, J Huang, Dh Hughes, T Kodama, Y Kang, S Kim, Pd Mauskopf, Ta Perera, Ks Scott
Astronomy Department Faculty Publication Series
We have undertaken a deep (σ∼ 1.1 mJy) 1.1-mm survey of the z= 0.54 cluster MS 0451.6−0305 using the AzTEC camera on the James Clerk Maxwell Telescope. We detect 36 sources with signal-to-noise ratio (S/N) ≥ 3.5 in the central 0.10 deg2 and present the AzTEC map, catalogue and number counts. We identify counterparts to 18 sources (50 per cent) using radio, mid-infrared, Spitzer InfraRed Array Camera (IRAC) and Submillimetre Array data. Optical, near- and mid-infrared spectral energy distributions are compiled for the 14 of these galaxies with detectable counterparts, which are expected to contain all likely cluster …
Total Infrared Luminosity Estimation Of Resolved And Unresolved Galaxies,
2010
University of Massachusetts Amherst
Total Infrared Luminosity Estimation Of Resolved And Unresolved Galaxies, M Boquien, G Bendo, D Calzetti, D Dale, C Engelbracht, R Kennicutt, Jc Lee, L Van Zee, J Moustakas
Astronomy Department Faculty Publication Series
The total infrared (TIR) luminosity from galaxies can be used to examine both star formation and dust physics. We provide here new relations to estimate the TIR luminosity from various Spitzer bands, in particular from the 8 μm and 24 μm bands. To do so, we use data for 45'' subregions within a subsample of nearby face-on spiral galaxies from the Spitzer Infrared Nearby Galaxies Survey (SINGS) that have known oxygen abundances as well as integrated galaxy data from the SINGS, the Local Volume Legacy survey (LVL), and Engelbracht et al. samples. Taking into account the oxygen abundances of the …
Dust Emission And Star Formation In Stephan's Quintet,
2010
University of Massachusetts - Amherst
Dust Emission And Star Formation In Stephan's Quintet, G Natale, Rj Tuffs, Ck Xu, Cc Popescu, J Fischera, U Lisenfeld, N Lu, P Appleton, M Dopita, P-A Duc, W Reach, J Sulentic, Min Yun
Astronomy Department Faculty Publication Series
We analyze a comprehensive set of MIR/FIR observations of Stephan's Quintet (SQ), taken with the Spitzer Space Telescope. Our study reveals the presence of a luminous (L IR 4.6 × 1043 erg s-1) and extended component of infrared dust emission, not connected with the main bodies of the galaxies, but roughly coincident with the X-ray halo of the group. We fitted the inferred dust emission spectral energy distribution of this extended source and the other main infrared emission components of SQ, including the intergalactic shock, to elucidate the mechanisms powering the dust and polycyclic aromatic …
Missing-Iron Problem And Type Ia Supernova Enrichment Of Hot Gas In Galactic Spheroids,
2010
University of Massachusetts - Amherst
Missing-Iron Problem And Type Ia Supernova Enrichment Of Hot Gas In Galactic Spheroids, S Tang, Qd Wang
Astronomy Department Faculty Publication Series
Type Ia supernovae (Ia SNe) provide a rich source of iron for hot gas in galactic stellar spheroids. However, the expected supersolar iron abundance of the hot gas is not observed. Instead, X-ray observations often show decreasing iron abundance towards galactic central regions, where the Ia SN enrichment is expected to be the highest. We examine the cause of this missing-iron problem by studying the enrichment process and its effect on X-ray abundance measurements of the hot gas. The evolution of Ia SN iron ejecta is simulated in the context of galaxy-wide hot gas outflows, in both supersonic and subsonic …
Supernova Remnants And The Interstellar Medium Of M83: Imaging And Photometry With The Wide Field Camera 3 On The Hubble Space Telescope,
2010
University of Massachusetts Amherst
Supernova Remnants And The Interstellar Medium Of M83: Imaging And Photometry With The Wide Field Camera 3 On The Hubble Space Telescope, Ma Dopita, Wp Blair, Ks Long, M Mutchler, Bc Whitmore, Kd Kuntz, B Balick, He Bond, D Calzetti, M Carollo, M Disney, Ja Frogel, R O'Connell, D Hall, Ja Holtzman, Ra Kimble, J Mackenty, P Mccarthy, F Paresce, A Saha, J Silk, M Sirianni, J Trauger, Ar Walker, R Windhorst, E Young
Astronomy Department Faculty Publication Series
We present Wide Field Camera 3 images taken with the Hubble Space Telescope within a single field in the southern grand design star-forming galaxy M83. Based on their size, morphology, and photometry in continuum-subtracted Hα, [S II], Hβ, [O III], and [O II] filters, we have identified 60 supernova remnant (SNR) candidates, as well as a handful of young ejecta-dominated candidates. A catalog of these remnants, their sizes and, where possible, their Hα fluxes are given. Radiative ages and pre-shock densities are derived from those SNRs that have good photometry. The ages lie in the range 2.62 < log (τrad/yr) < 5.0, and the pre-shock densities at the blast wave range over 0.56 < n 0/cm-3 < 1680. Two populations of SNRs have been discovered. These divide into a nuclear and spiral arm group and an inter-arm population. We infer an arm to inter-arm density contrast of 4. The surface flux in diffuse X-rays is correlated with the inferred pre-shock density, indicating that the warm interstellar medium (ISM) is pressurized by the hot X-ray plasma. We also find that the ISM in the nuclear region of M83 is characterized by a very high porosity and pressure, and infer an SNR rate of 1 per 70-150 yr for the nuclear (R < 300 pc) region. On the basis of the number of SNRs detected and their radiative ages, we infer that the lower mass of Type II SNe in M83 is M min = 16+7 –5 M . Finally, we give evidence for the likely detection of the remnant of the historical supernova, SN1968L.
Molecular And Atomic Gas In The Local Group Galaxy M 33,
2010
University of Massachusetts Amherst
Molecular And Atomic Gas In The Local Group Galaxy M 33, Gratier, Braine, Rodriguez-Fernandez, Schuster, Kramer, Xilouris, Tabatabaei, Henkel, Corbelli, Israel, Van Der Werf, D Calzetti
Astronomy Department Faculty Publication Series
We present high-resolution large-scale observations of the molecular and atomic gas in the Local Group galaxy M 33. The observations were carried out using the HEterodyne Receiver Array (HERA) at the 30 m IRAM telescope in the CO(2–1) line, achieving a resolution of 12″ × 2.6 km s-1, enabling individual giant molecular clouds (GMCs) to be resolved. The observed region is 650 square arcminutes mainly along the major axis and out to a radius of 8.5 kpc, and covers entirely the 2′ × 40′ radial strip observed with the HIFI and PACS Spectrometers as part of the HERM33ES Herschel key …
Submillimeter Array Identification Of The Millimeter-Selected Galaxy Ssa22-Aztec1: A Protoquasar In A Protocluster?,
2010
University of Massachusetts - Amherst
Submillimeter Array Identification Of The Millimeter-Selected Galaxy Ssa22-Aztec1: A Protoquasar In A Protocluster?, Y Tamura, D Iono, Dj Wilner, M Kajisawa, Yk Uchimoto, Dm Alexander, A Chung, H Ezawa, B Hatsukade, T Hayashino, Dh Hughes, T Ichikawa, S Irkarashi, R Kawabe, K Kohno, Bd Lehmer, Y Matsuda, K Nakanishi, T Takata, Gw Wilson, T Yamada, Min Yun
Astronomy Department Faculty Publication Series
We present results from Submillimeter Array (SMA) 860 μm subarcsecond astrometry and multiwavelength observations of the brightest millimeter (S 1.1mm = 8.4 mJy) source, SSA22-AzTEC1, found near the core of the SSA22 protocluster that is traced by Lyα-emitting galaxies at z = 3.09. We identify a 860 μm counterpart with a flux density of S 860 μm = 12.2 ± 2.3 mJy and absolute positional accuracy that is better than 03. At the SMA position, we find radio-to-mid-infrared counterparts, whilst no object is found in Subaru optical and near-infrared deep images at wavelengths ≤1 μm (J > 25.4 in …
A High-Resolution Line Survey Of Irc +10216 With Herschel/Hifi *,** First Results: Detection Of Warm Silicon Dicarbide (Sic),
2010
University of Massachusetts - Amherst
A High-Resolution Line Survey Of Irc +10216 With Herschel/Hifi *,** First Results: Detection Of Warm Silicon Dicarbide (Sic), J Cernicharo, Lbfm Waters, L Decin, P Encrenaz, Aggm Tielens, M Agundez, E Debeck, Hsp Muller, Jr Goicoechea, Mj Barlow, A Benz, N Crimier, F Daniel, Am Digiorgio, M Fich, T Gaier, P Garcia-Lario, A Dekoter, T Khouri, R Liseau, R Lombaert, Nr Erickson, Jr Pardo, Jc Pearson, R Shipman, C Sanchez Contreras, D Teyssier
Astronomy Department Faculty Publication Series
We present the first results of a high-spectral-resolution survey of the carbon-rich evolved star IRC+10216 that was carried out with the HIFI spectrometer onboard Herschel. This survey covers all HIFI bands, with a spectral range from 488 to 1901 GHz. In this letter we focus on the band-1b spectrum, in a spectral range 554.5–636.5 GHz, where we identified 130 spectral features with intensities above 0.03 K and a signal-to-noise ratio >5. Detected lines arise from HCN, SiO, SiS, CS, CO, metal-bearing species and, surprisingly, silicon dicarbide (SiC2). We identified 55 SiC2 transitions involving energy levels between …
A Spitzer View Of Star Formation In The Cygnus X North Complex,
2010
University of Massachusetts - Amherst
A Spitzer View Of Star Formation In The Cygnus X North Complex, I. M. Beerer, X. P. Koenig, J. L. Hora, R. A. Gutermuth
Astronomy Department Faculty Publication Series
We present new images and photometry of the massive star-forming complex Cygnus X obtained with the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer for Spitzer (MIPS) on board the Spitzer Space Telescope. A combination of IRAC, MIPS, UKIRT Deep Infrared Sky Survey, and Two Micron All Sky Survey data are used to identify and classify young stellar objects (YSOs). Of the 8231 sources detected exhibiting infrared excess in Cygnus X North, 670 are classified as class I and 7249 are classified as class II. Using spectra from the FAST Spectrograph at the Fred L. Whipple Observatory and Hectospec …
The Physical Scale Of The Far-Infrared Emission In The Most Luminous Submillimetre Galaxies – Ii. Evidence For Merger-Driven Star Formation,
2010
University of Massachusetts - Amherst
The Physical Scale Of The Far-Infrared Emission In The Most Luminous Submillimetre Galaxies – Ii. Evidence For Merger-Driven Star Formation, Jd Younger, Gg Fazio, Mln Ashby, F Civano, Ma Gurwell, J-S Huang, D Iono, Ab Peck, Gr Petitpas, Ks Scott, Dj Wilner, Gw Wilson, Min Yun
Astronomy Department Faculty Publication Series
We present high-resolution 345-GHz interferometric observations of two extremely luminous (Lir≳ 1013 L⊙), submillimetre-selected galaxies (SMGs) in the Cosmic Evolution Survey (COSMOS) field with the Submillimeter Array (SMA). Both targets were previously detected as unresolved point sources by the SMA in its compact configuration, also at 345 GHz. These new data, which provide a factor of ≳3 improvement in resolution, allow us to measure the physical scale of the far-infrared in the submillimetre directly. The visibility functions of both targets show significant evidence for structure on ∼0.5–1-arcsec scales, which at z≳ 1.5 translates …
Mid-Infrared Spectroscopy Of Candidate Active Galactic Nuclei-Dominated Submillimeter Galaxies,
2010
University of Massachusetts - Amherst
Mid-Infrared Spectroscopy Of Candidate Active Galactic Nuclei-Dominated Submillimeter Galaxies, K Coppin, A Pope, K Menendez-Delmestre, Dm Alexander, Js Dunlop, E Egami, J Gabor, E Ibar, Rj Ivison, Je Austermann, Aw Blain, Sc Chapman, Dl Clements, L Dunne, S Dye, D Farrah, Dh Hughes, Amj Mortier, Mj Page, M Rowan-Robinson, D Scott, C Simpson, I Smail, Am Swinbank, M Vaccari, Min Yun
Astronomy Department Faculty Publication Series
Spitzer spectroscopy has revealed that 80% of submm galaxies (SMGs) are starburst (SB)-dominated in the mid-infrared. Here we focus on the remaining 20% that show signs of harboring powerful active galactic nuclei (AGNs). We have obtained Spitzer-InfraRed Spectrograph spectroscopy of a sample of eight SMGs that are candidates for harboring powerful AGNs on the basis of IRAC color selection (S 8 μm/S 4.5 μm>2, i.e., likely power-law mid-infrared spectral energy distributions). SMGs with an AGN dominating (50%) their mid-infrared emission could represent the "missing link" sources in an evolutionary sequence involving a major merger. First …
Mapping Far-Ir Emission From The Central Kiloparsec Of Ngc 1097,
2010
University of Massachusetts - Amherst
Mapping Far-Ir Emission From The Central Kiloparsec Of Ngc 1097, K Sandstrom, O Krause, H Linz, E Schinnerer, G Dumas, S Meidt, H Rix, M Sauvage, F Walter, R Kennicutt, D Calzetti
Astronomy Department Faculty Publication Series
Using photometry of NGC 1097 from the Herschel PACS (Photodetector Array Camera and Spectrometer) instrument, we study the resolved properties of thermal dust continuum emission from a circumnuclear starburst ring with a radius ~900 pc. These observations are the first to resolve the structure of a circumnuclear ring at wavelengths that probe the peak (i.e. λ ~ 100 μm) of the dust spectral energy distribution. The ring dominates the far-infrared (far-IR) emission from the galaxy – the high angular resolution of PACS allows us to isolate the ring's contribution and we find it is responsible for 75, 60 and 55% …
Pressure Support Versus Thermal Broadening In The Lyman Alpha Forest - I. Effects Of The Equation Of State On Longitudinal Structure,
2010
University of Massachusetts - Amherst
Pressure Support Versus Thermal Broadening In The Lyman Alpha Forest - I. Effects Of The Equation Of State On Longitudinal Structure, Ms Peeples, Dh Weinberg, R Dave, Ma Fardal, N Katz
Astronomy Department Faculty Publication Series
In the low-density intergalactic medium that gives rise to the Lyman α (Lyα) forest, gas temperature and density are tightly correlated. The velocity scale of thermal broadening and the Hubble flow across the gas Jeans scale are of similar magnitude (HλJ∼σth). To separate the effects of gas pressure support and thermal broadening on the Lyα forest, we compare spectra extracted from two smoothed particle hydrodynamics simulations evolved with different photoionization heating rates (and thus different Jeans scales) and from the pressureless dark matter distribution, imposing different temperature–density relations on the evolved particle distributions. The …
Spitzer Observations Of The Λ Orionis Cluster. Ii. Disks Around Solar-Type And Low-Mass Stars,
2010
University of Massachusetts - Amherst
Spitzer Observations Of The Λ Orionis Cluster. Ii. Disks Around Solar-Type And Low-Mass Stars, Jesús Hernández, Maria Morales-Calderon, Nuria Calvet, L. Hartmann, J. Muzerolle, R. Gutermuth
Astronomy Department Faculty Publication Series
We present IRAC/MIPS Spitzer Space Telescope observations of the solar-type and the low-mass stellar population of the young (~5 Myr) λ Orionis cluster. Combining optical and Two Micron All Sky Survey photometry, we identify 436 stars as probable members of the cluster. Given the distance (450 pc) and the age of the cluster, our sample ranges in mass from 2 M sun to objects below the substellar limit. With the addition of the Spitzer mid-infrared data, we have identified 49 stars bearing disks in the stellar cluster. Using spectral energy distribution slopes, we place objects in several classes: non-excess stars …
The Globular Cluster System Of Ngc 1399. V. Dynamics Of The Cluster System Out To 80 Kpc,
2010
Universidad Nacional de La Plata
The Globular Cluster System Of Ngc 1399. V. Dynamics Of The Cluster System Out To 80 Kpc, Y. Schuberth, T. Richtler, M. Hilker, B. Dirsch, L. Bassino, Aaron J. Romanowsky, L. Infante
Aaron J. Romanowsky
Globular clusters (GCs) are tracers of the gravitational potential of their host galaxies. Moreover, their kinematic properties may provide clues for understanding the formation of GC systems and their host galaxies. We use the largest set of GC velocities obtained so far of any elliptical galaxy to revise and extend the previous investigations (Richtler et al. 2004) of the dynamics of NGC 1399, the central dominant galaxy of the nearby Fornax cluster of galaxies. The GC velocities are used to study the kinematics, their relation with population properties, and the dark matter halo of NGC 1399. We have obtained 477 …
The Stellar And Gaseous Contents Of The Orion Dwarf Galaxy,
2010
Macalester College
The Stellar And Gaseous Contents Of The Orion Dwarf Galaxy, John M. Cannon, Korey Haynes, Hans Most, John J. Salzer, Kaitlin Haugland, Jillian Scudder, Arthur Sugden, Jacob Weindling
John Cannon
No abstract provided.
